Hydrochloric Acid Lock Therapy for Catheter-Related Bloodstream Infections: In Vitro Antimicrobial Activity and...

Area of Science:

• Infectious Diseases
• Biomaterials Science
• Antimicrobial Therapy

Background:

• Catheter-related bloodstream infections (CRBSIs) pose a significant clinical challenge, often driven by antibiotic-resistant, biofilm-forming bacteria.
• Hydrochloric acid lock therapy (HALT) is utilized in Denmark for catheter salvage, but its in vitro efficacy and material compatibility require thorough investigation.

Purpose of the Study:

• To evaluate the antimicrobial efficacy of hydrochloric acid (HCl) against common CRBSI pathogens in biofilm.
• To assess the impact of HCl exposure on the mechanical integrity and surface characteristics of silicone and polyurethane central venous catheters.

Main Methods:

• Biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis were cultured in vitro.
• Biofilm samples and catheter segments were treated with 2 M HCl or saline.
• Mechanical testing (tensile strength) and optical microscopy were performed on treated catheter segments.

Main Results:

• HCl significantly reduced bacterial viability in biofilms by up to 5.4 log10 CFU/mL in well plates and 4.1 log10 CFU/mL on catheters.
• No bacterial growth was detected on catheter segments post-HCl treatment.
• HCl exposure did not compromise the tensile strength or surface integrity of silicone or polyurethane catheters.

Conclusions:

• Hydrochloric acid demonstrates potent antimicrobial activity against CRBSI biofilms.
• HCl treatment does not adversely affect the material integrity of central venous catheters.
• HALT warrants further investigation as an adjunctive therapy for managing CRBSIs.